Drinking Water and Public Health

1. Drinking Waterand Public Health OSU Summer Environmental Institute July 13, 2009 Dr. Anna Harding, Professor Jessica Nischik, MPH Student Evan Miles, MS Student

2. Presentation Topics • What is public health? • Link between water and public health • Global water-related disease incidence • Reduced illness related to water supply improvements • Water-related disease types • Drinking water contaminants and health effects • Global response to improving access—MDGs • Drinking water guidelines, surveillance, and community management • Drinking water guidelines and standards • Basic drinking water treatment and disinfectants • Low-cost alternative household treatments • Surveillance and quality control of drinking water • Public Health authorities • Local authorities and community management of water supplies

3. Introducing Public Health • What is Public Health? • The art and science of safeguarding and improving community health through organized community effort involving prevention of disease, control of communicable disease, application of sanitary measures, health education and monitoring of environmental hazards.

4. Public Health Professionals: • Monitor health status to identify community health problems. • Diagnose and investigate health problems and health hazards in the community. • Inform, educate, and empower people about health issues. • Mobilize community partnerships to identify and solve health problems. • Develop policies and plans that support individual and community health efforts.

5. Public Health Professionals: • Enforce laws and regulations that protect health and ensure safety. • Link people to needed personal health services and assure provisions of health care when otherwise unavailable. • Assure a competent public health and personal health care work force. • Research new insights and innovative solutions to health problems.

6. Water as a Basic Human Right • “All people, whatever their stage of development and social and economic condition, have the right to have access to drinking water in quantities and of a quality equal to their basic needs.” (UN Conference at Mar del Plata, 1977) • “The human right to water entitles everyone to sufficient, safe, acceptable, physically accessible and affordable water for personal and domestic uses.” (WHO, 2002)

7. Water-related Disease Incidence Water-related diseases account for 80% of all deaths in developing countries Infectious and parasitic diseases are major cause of morbidity (illness) Many water-related diseases lead to epidemics with high death rates (e.g. cholera)

8. Water and Sanitation–related Diseases Cases per year Deaths per year Amoebiasis Arsenic Diarrhoeal disease, Including cholera Dracunuliasis (guinea worm) Fluorosis Giardiasis Hepatitis A Intestinal helminths Malaria Schistosomiasis Trachoma Typhoid 48,000,000 28-35m exposed to drinking water with elevated levels 1.5 billion > 5000 26 million (China) 500,000 1,500,00 133,000,000 396,000,000 160,000,000 500,000,000 500,000 110,000 1,800,000 - - Low - 9400 1,300,000 > 10,000 - 25,000

9. Global Water and Sanitation Coverage • What are the facts on your country’s water and sanitation coverage? • Water and Sanitation Assessment 2000 Report • http://www.who.int/water_sanitation_health/monitoring/jmp2000.pdf • World Health Statistics • http://www.who.int/whosis/whostat/EN_WHS09_Table5.pdf • WHO detailed database • http://apps.who.int/whosis/data/Search.jsp?indicators=[Indicator].[RF].Members

10. Water Supply Improvementsand Reduced Disease • Improved water supply and sanitation will lead to reduced illness and death—may be up to 100% for some diseases (typhoid) • Improved access to safe drinking water increased from 4.1 billion (1990) to 5.7 billion (2006) • Improved sanitation increased from 3 billion (1990) to 4 billion (2006) • What is the increase in your countries?

11. Morbidity Reductions Due to Improved Water Supply Projected reduction in Morbidity (%) 25-32 100 29 (Ascariasis) 4 (Hookworm) 77 27 Diseases Diarrhoeal diseases, dysentery, gastroenteritis, cholera, typhoid Dracunuliasis Intestinal helminths (Ascariasis, Trichariasis Hookworm) Schistosomiasis Trachoma

12. Infant Mortality Versus Access to Safe Water • Infant mortality rates (sentinel indicator of health) impacted by improved water supply

13. Water–related Disease Types • Many different types of water-related diseases—not all are fatal, but all are debilitating • Diseases classified on basis of transmission • Some classified in more than one group—e.g. diarrheal disease transmitted by waterborne route but also related to inadequate quantities

14. Water and Sanitation–Related Diseases Group Waterborne diseases (diseases transmitted by water) Water-washed privation diseases (caused by lack of water) Water-based diseases Water-related insect vector diseases Water-dispersed infections Diseases Cholera; Typhoid; Bacillary dysentery; Infectious hepatitis; Giardiasis; Cryptosporidiosis Scabies; Skin sepsis and Ulcers; Yaws, Leprosy; Trachoma; Dysenteries; Ascariasis Schistomiasis; Dracunuliasis; Bilharziosis; Filariasis Yellow fever; Dengue fever; Malaria; Onchocerciasis Japanese encephalitis Legionella

15. Classical Waterborne Infection Cycle • Water is important medium for transmitting disease Diseases often transmitted via fecal-oral route • Fecal matter ingested through drinking contaminated water

16. Global Response to Improving Access–MDGs • September 2000, 189 heads of state adopted the UN Millennium Declaration • Plan was for countries and development partners to work together to increase access to the resources needed to reduce poverty and hunger, and tackle ill-health, gender inequality, lack of education, lack of access to clean water and environmental degradation. • 8 Millennium Development Goals (MDGs), set targets for 2015, and identified a number of indicators for monitoring progress, several of which relate directly to health. • All goals and their targets are measured in terms of progress since 1990. • MDG #7--Halve the proportion of people without sustainable access to safe drinking water and basic sanitation

17. Major Drinking Water Contaminants and Health Effects • Contaminants may produce acute (severe onset w/in short period of time) or chronic (occur and persist as long-term use) effects. • Groups at high risk to contaminated water include: • pregnant and nursing women • the elderly • infants • ill or malnourished people

18. Microbiological Contaminants • Microbiological contaminants are of most significance in both developing and developed countries and responsible for spread of infectious and parasitic diseases, such as cholera, typhoid, dysentery, hepatitis, giardiasis,schistosomiasis

19. Inorganic Contaminants • Inorganics (heavy metals, nitrate) • Sources are industrial practices, runoff from fertilizer, mining wastes, septic tank failures) • Heavy metals may cause permanent brain damage, harm organs (kidneys, liver), and some are carcinogenic • mercury, arsenic, cadmium, lead • Nitrates above 10 mg/L may cause methemogobinemia (blue baby) in children younger than 2 yrs.

20. Organic Contaminants • Synthetic Organics and Volatile Organics (VOCs) (TCE, lindane, dioxin, benzene, disinfectant by-products) • Sources are pesticide runoff, chemical solvents, household products, leaking underground gas tanks. • Increasing number of synthetic organic compounds being introduced into the environment

21. Radionuclide Contaminants • Radionuclides (radon, uranium) • Sources are groundwater contamination, naturally occurring in bedrock (check to see if your country is a “hot spot” for radon) • Radionuclides undergo process of natural decay, emit radiation • Showering, laundering, dishwashing agitate water and release radon into air • Radiation is carcinogenic at certain exposure levels and concentrations

22. Drinking Water Guidelines and Standards • WHO Guidelines provide framework for safe drinking water—five components—applicable to large metropolitan and small community piped drinking water systems, and also to non-piped drinking water systems in communities • Advisory in nature and intended to be used by national or regional authorities—not strict standards as in US • Health-based targets based on health concerns • System assessment to determine if source of drinking water can deliver water that meets health-based targets • Monitoring of drinking water supply to ensure safe drinking water • Management plans documenting system monitoring, upgrades, communication • System of independent surveillance to verify that system is operating properly

23. WHO Guidelines • WHO Guidelines priority is on microbiological quality of drinking water • Diseases associated with water are concentrated in developing countries, and among poorer urban and rural households • Diseases associated with ingestion have greatest impact • Microorganisms selected in Guidelines on basis of presence in water and likely risk to human health • Selection criteria • Substance presents potential hazard for human health over lifetime of consumption (chemicals) or with infective dose (microbes) • Substance is detected frequently and at high concentrations and there is significant exposure to humans • Substance is of international concern • Guideline values set for indicator bacteria, operational parameters (turbidity and chlorine residual), and for 95 chemicals

24. Microbiological Indicators • Detect and enumerate indicator organisms rather than the pathogens themselves (no lower tolerable limit for pathogens) • Must be consistently and exclusively associated with the pathogen • Indicators are chosen because they are easier and/or cheaper to detect than the pathogen • Have same resistance to disinfectants and environmental stress as most resistant pathogens • Should not multiply under environmental conditions • As indicators of potential fecal pollution, coliform bacteria are the EPA-approved method and WHO Guideline • More numerous and easier to find than pathogens • Rarely get negative test when fecal-born pathogen is present • Most common indicators are total coliforms and E.coli • Should be zero total coliforms in 100 ml of drinking water

25. US–EPA Drinking Water Standards • EPA requires public systems to meet or exceed federal drinking water standards • Standards or Maximum contaminant levels (MCLs) set for more than 80 contaminants • Primary standards are health-based, enforced • National Primary Drinking Water Standards and website: • http://www.epa.gov/safewater/contaminants/index.html#mcls • Secondary standards are set for aesthetics (iron, manganese, color, total dissolved solids) • Local utilities must publish annual drinking water quality report: • http://www.ci.corvallis.or.us/downloads/pw/wqreport.pdf

26. US Drinking Water Testing and Reporting • State health departments regulate testing and reporting for EPA. • Local municipality tests, treats water • monitoring schedule depends on contaminant and size of community water system • reports sent to state health department • must alert public if violations occur • State health department collects state data, regulates for EPA • Centers for Disease Control and Prevention collects national data on outbreaks; EPA collects test data

27. Basic Drinking Water Treatment • Treatment facilities use basic treatment to remove contaminants: • initial screening • flocculation/sedimentation to combine small particles into larger ones • filtration to remove particles, clarify water (mixed media) • ion exchange (inorganics), adsorption (organics, color, taste) optional • disinfection (chlorination, ozone, UV, others) • must kill pathogens and provide residual

28. Disinfection of Drinking Water • Basic disinfection requirements: • Primary disinfection: inactivates pathogens • takes into account concentration and time of contact (C*T) • Secondary disinfection: prevent subsequent growth in delivery system and protection from cross-contamination • Cost considerations

29. Disinfectants • Free Chlorine (Cl2)- compressed gas • also Na OCl and Ca (OCl)2 • effective primary disinfectant (lower pH desirable) • stable residual • oxidizes iron, sulfides, color, manganese • Cl2 + H2O = H+ + Cl- + HOCl (hypochlorous acid) • HOCl > H+ OCl- (hypochloric acid) • HOCl less apt to disassociate--disassociated HOCl acts as disinfectant • Equilibrium between undissociated HOCl, H+ and OCl- based on pH • At low pH (acidic condition), HOCl predominates—disinfection with chlorine more efficient at lower pH values (optimal values between pH 5.5-7.5) • With pH =6, HOCl is 80% and whereass the concentration OCl- is 20%. When pH=8, this is the other way around.When the pH value is 7.5, concentrations of HOCl and OCl- are equally high. • Disadvantage—Cl2 forms TTHMs and other halogenated byproducts

30. able 1: disinfection time for several different types of pathogenic microorganisms with chlorinated water, containing a chlorine concentration of 1 mg/L (1 ppm) when pH = 7,5 and T = 25 °C able 1: disinfection time for several different types of pathogenic microorganisms with chlorinated water, containing a chlorine concentration of 1 mg/L (1 ppm) when pH = 7,5 and T = 25 °C able 1: disinfection time for several different types of pathogenic microorganisms with chlorinated water, containing a chlorine concentration of 1 mg/L (1 ppm) when pH = 7,5 and T = 25 °C Disinfectants • Disinfectant time for pathogens differs—examples of fecal pollutants usingchlorine concentration of 1 mg/L (1 ppm) when pH = 7,5 and T = 25 °C • E. coli 0157 H7 bacterium< 1 minute • Hepatitis A virusabout 16 minutes • Giardia parasiteabout 45 minutes • Cryptosporidium about 9600 minutes http://www.lenntech.com/water-disinfection/disinfectants-chlorine.htm#ixzz0KsHtUBXL&D http://www.lenntech.com/water-disinfection/disinfectants-chlorine.htm#ixzz0KsHtUBXL&D http://www.lenntech.com/water-disinfection/disinfectants-chlorine.htm#ixzz0KsHtUBXL&D

31. Disinfectants • Chloramines- combined chlorine • Chloramines formed during a reaction between Cl2 and ammonia (NH3)—ammonia added to water containing free chlorine (HOCl or OCl- depending on pH) • NH3 (aq) + HOCI -> NH2Cl + H2O • pH value does not interfere with the effectiveness of chloramines • weak disinfectant for Girardia, viruses, but stable residual • not effective oxidants for color, iron, manganese • low TTHM formation

32. Disinfectants • Chlorine Dioxide (ClO2) • requires complex equipment • strong disinfectant, does not react with ammonia • decays slowly, stable residual for secondary disinfection • no TTHM formation, but health concerns for degradation products • removes color, taste and odor inc. phenols • may be alternative for virus, cyst inactivation • UV Radiation • radiation produced by UV lamps • effective primary disinfectant for viruses, not effective for Giardia—possible application for groundwater • no residuals formed, no disinfectant by-products • Effective on small scale—e.g. UV disinfection in bottles

33. Disinfectants • Ozone (O3) • highly reactive—process of passing ozone through water • Commonly used in Europe, increasing use in US • does not provide a residual • inactivates viruses and all pathogens • most expensive • oxidizes iron, manganese, color, taste and odor • forms bromate, possibly human carcinogen

34. Household Treatment—Physical Methods (a) Categories for annual household cost estimates in US dollars are less than $10 for low, >$10-100 for moderate and >$100 for high.(b) Categories for microbial efficacy are based on estimated order-of-magnitude or log10 reductions of waterborne microbes by the treatment technology. The categories are <1 log10 (<90%) is low, 1 to 2 log10 (90-99%) is moderate and >2 log10 (>99% is high).

35. Household Treatment—Chemical or Physical-Chemical Methods

36. Surveillance and Quality Control • Separate roles for water supplier and authority responsible for independent oversight • Surveillance: “the continuous and vigilant public health assessment and review of the safety and acceptability of drinking-water supplies” • Surveillance requires a systematic program of surveys, audits, analysis, sanitary inspection, and community aspects • National agencies provide a framework of targets, standards, and legislation • Water suppliers are required to meet these standards

37. Surveillance and Quality Control • Independent agency (usually Ministry of Health or Environment) is responsible for surveillance • Surveillance agency must be supported by strong and enforceable legislation

38. Public Health Authorities • National entities have responsibilities in four major areas • Surveillance of health status and trends, including outbreak investigations • Establish drinking water norms and standards (e.g., US MCLs) • Represent health concerns in wider policy development • Provide guidance in surveillance of drinking water supplies either directly or through regional/local environmental health authorities

39. Public Health Surveillance • Public health surveillance teams operate at national, regional, and local levels • Routine surveillance includes: • Ongoing monitoring of reportable diseases, many of which may be caused by waterborne pathogens • Outbreak detections • Long-term trend analysis • Geographic and demographic analysis • Feedback to water authorities • Epidemiological studies to determine the role of water as a risk factor in disease

40. Public Health Authority Deliverables • Periodic reports outlining national drinking water quality • Reports highlighting public health concerns and priorities • Formulation and implementation of policy to ensure access to reliable, safe drinking water supply

41. Local Public Health Authorities • Play an important role in managing water resources and drinking water supplies • May be responsible for: • Guidance in designing and implementing community and household drinking water systems • Guidance for correcting deficiencies • Surveillance of community and household drinking water supplies • Educate consumers where household water treatment is necessary, including: • Water and sanitation and health education • Basic technical training in drinking water supply and management • Overcoming sociocultural barriers to acceptance of water quality interventions • Providing a system of continued support to achieve sustainability

42. Community Managed Water Systems • Common worldwide, with both piped and non-piped distribution • Management often relies on untrained, unpaid community members • Community members, including women, must be actively involved in all stages of the program • Stages of program support and involvement : • Initial surveys • Decisions on siting of wells • Siting of protection zones • Monitoring and surveillance of drinking-water supplies • Reporting problems • Carrying out maintenance and taking remedial action • Education regarding sanitation and hygiene practices

43. Community health education • Education programs should ensure: • Community awareness of need for drinking water quality and relation to health • Recognition of the importance for surveillance and need for community response • Understanding and preparedness, including necessary skills, for participating in surveillance process • Awareness of requirements for protection of drinking-water supplies from pollution